Solution:A diversion headwork serves to divert the required supply into the canal from the river. A diversion headwork serves the following purposes:1. It raises the water level in the river so that the commanded area can be increased.
2. It regulates the intake of water into the canal.
3. It controls the silt entry into the canal.
4. It reduces fluctuations in the level of supply in the river.
5. It stores water for tiding over small periods of short supplies.
A diversion headwork can further be sub-divided into two principal classes:
1. Temporary spurs or bunds.
2. Permanent weirs and barrages.
Temporary spurs or bunds are those which are temporary and are constructed every year after the floods. However, for important works, weirs or barrages are constructed since they are of permanent nature if designed properly.